A late-stage clinical trial of the Oxford/AstraZeneca coronavirus vaccine found the shot was effective in preventing COVID-19 — and reported no evidence of the thrombosis-related events that have concerned EU countries, AstraZeneca announced on Monday.
The vaccine was able to prevent all severe disease and hospitalization, as well as 79 percent of symptomatic cases of COVID-19, according to the U.S.-based Phase 3 study. Among participants 65 years and older, the vaccine was 80 percent effective, a notable result given early doubts around lack of data for older patients in Europe.
Data collected from the 32,449 participants showed “no safety concerns related to the vaccine,” said AstraZeneca.
The trial’s independent data safety monitoring board specifically analyzed the results for thrombosis and found no increased risk, and there were no instances of rare cerebral venous sinus thrombosis, which had worried Germany’s Paul-Ehrlich-Institut.
The study results come after a review of vaccines safety data conducted by the European Medicines Agency following a number of instances of thrombosis in patients who were administered the vaccine in EU countries, prompting them to suspend the shot.
The drug regulator gave the Oxford/AstraZeneca vaccine the all clear last week, after its safety committee PRAC concluded the vaccine is “not associated with an increase in the overall risk of thromboembolic events or blood clots.”
Most countries who had paused distribution of the vaccine resumed administering it. However, over the weekend, Denmark reported one death and one hospitalization after the shot, and vaccinations with the jab there remain suspended.